Grist-mill



O. WYMAN.

Grist Mill.

Patented April 18,1839.

UNITED STATES PATENT OFFICE.

OLIVER WYMAN, OF EAST CAMBRIDGE, MASSACHUSETTS.

GRIST-MILL.

Specification of Letters Patent No. 1,125, dated. April 18, 1839'.

To all whom it may concern Be it known that I, OLIVER VVYMAN, of EastCambridge, Middlesex county, State of Massachusetts, have invented a newand use ful Improvement in Mills for Grinding Grain and OtherSubstances, called lVymans Improved Grist-Mill, which is described asfollows, reference being had to the annexed drawings of the same, makingpart of this specification.

Figure 1, is a perspective view of the machine. Fig. 2, is a view of therunner. Fig. 8, is a view of the bed-stone. Fig. 4:, is a verticalsection. Fig. 5, section of the curb. Fig. 6, section of thebridge-tree. Fig. 7, section showing the inverted bow-spring and thesocket into which the upper end of the spindle is inserted.

The letters of reference refer to the same parts in the several figures.

This mill consists of a frame of suitable size and strength composed offour posts A, A, A, A, and four girts B, B, B, B, mortised and tenonedtogether. Between these posts and upon the two upper side girts isplaced a platform C, having an aperture in the center for the spindle topass through and another aperture at the side through which the meal isdischarged. Upon this platform is placed a curb D in which the runner Rturns, having four oblique apertures therein to admit air for coolingthe meal. These air holes are made in the curb in the direction of theturning of the runner (which has rings on its circumference) so that asthe runner revolves a draft is created inward which cools the meal asjust mentioned. Each air hole is made of a rectangular or oblong shapeof a. size proportionate to that of the curb.

The runner is shaped conical on the upper or grinding surface andfurrowed in the usual manner, it is about 24 inches in diameter, 14Linches in depth in the center, and 6 inches at the edge. A square socketis fitted into the center of the runner and secured by cement in theusual manner which receives the square end of the spindle by which theyare connected and caused to turn together.

The spindle turns in a step secured on the bridge tree F, which israised or lowered by screws as required. These screws (one on each end)pass through bars G supported on the two lower side-girts. Thebridgetree being elevated or depressed at pleasure by said screws whichraises or lowers the runner as required to suit the kind of grinding tobe done. The ends of the bridge tree are tenoned and move incorresponding mortises in the side girts causing the bridge tree andspindle to move vertically. The spindle turns in a box fixed in a crossgirt under the platform and is provided with a driving pulley P and flywheel W of the usual construction.

The upper or stationary stone S is made in one or two pieces; concave onthe under side corresponding in shape with the conical face of therunner which turns therein and is furrowed in the usual manner. It hasan opening in the center to admit the grain and also the shaking staff Hfor shaking the,

shoe; which staff passes into a square opening in the top of the runnerand turns with it. This upper or stationary stone rests upon the curband is held down upon it firmly by means of screws I passing throughmovable cross binders E whose ends are tenoned and move in grooves inthe inside of the two upper end girts.

The hopper J and meal trough M are made in the usual manner.

The runner R is suspended on the top of the spindle by means of aninverted bow spring X which is let into a cavity made in the runner, soas to allow the runner to accommodate itself to the bed, in grinding.There are two or four wings Y placed on the periphery of the runner tocreate draft for keeping the meal cool. The dimensions of the severalparts may be varied to suit circumstances.

The invention claimed and desired to be secured by Letters Patentconsists in Perforating the curb obliquely in the direction of theturning of the runner for the purpose of admitting air for cooling themeal and in combination therewith, the wings on the periphery of therunner for producing a draft through the oblique opening in the curb.

' OLIVER WYMAN. Witnesses N. BENEDICT, WM. BISHOP.

